Ivan Bella created ACCUMULO-4391:
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Summary: Source deepcopies cannot be used safely in separate
threads in tserver
Key: ACCUMULO-4391
URL: https://issues.apache.org/jira/browse/ACCUMULO-4391
Project: Accumulo
Issue Type: Bug
Components: core
Affects Versions: 1.6.5
Reporter: Ivan Bella
Assignee: Ivan Bella
Fix For: 1.6.6
We have iterators that create deep copies of the source and use them in
separate threads. As it turns out this is not safe and we end up with many
exceptions, mostly down in the ZlibDecompressor library. Curiously if you turn
on the data cache for the table being scanned then the errors disappear.
After much hunting it turns out that the real bug is in the
BoundedRangeFileInputStream. The read() method therein appropriately
synchronizes on the underlying FSDataInputStream, however the available()
method does not. Adding similar synchronization on that stream fixes the
issues. On a side note, the available() call is only invoked within the hadoop
CompressionInputStream for use in the getPos() call. That call does not appear
to actually be used at least in this context.
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